Refrigerating apparatus



sept 21, 193?. J. R KILLEN 2,0sxs39 REFRIGERATING APPARATUS =.gina1 Filed not. 61952 2 sheets-sheet 1 5e 4a 2 37 c o e 42 s2 v 41 Sept 21, 1937. J. R. KILLEN 2,093,839

REFRIGERATING APPARATUS Qrigipal Filed Oct. 6, 1952 2 Sheets-Sheet 2 7l 8g Y 84 64 81 amarres aaraioaaa'rrna .irranaans This invention relates lames lit. Kilian, Dayton.

assignments, to General Meters @hid assigner, by mesme tlorporation, a

corpcration nf Delaware Application @ctober d, i932, Serial No. 635.51%@ Renewed August 9. i935 ll@ Claims.

to refrigerating apparatus and more particularly to that type of cooling apparatus commonly called beverage coolers or water coolers.

In these types oi coolers I have found that there vare a number of diculties involved. One of these is that of providing a very dependable and accurate control of the temperature of the beverage, water, or other fluid which is to be used. In fact, one of the difculties is to prevent the beverage, water or other fluid from freezing during periods of inactivity when no uiol is being used.

It is therefore one of the objects of my invention to provide dependable and accurate means for controlling the final being cooled in a cooling temperature of the fluid apparatus.

More specifically, it is an object of my invention to provide a cooling apparatus having a primary and a secondary refrigerating system with a control for the primary evaporating system actuated by and responsive to the temperature of the secondary system for accurately controlling the final temperature of the fluid It is also necessary to to clean the tubes or con being cooled. provide a way in which duits through which the beverage, water or other iiuid flows. This is ordinarily done by passing live steam or hot cleaning solution through the tubes or conduits in order to remove the dirt, scale, deposits or any type of fungus growth which may grow within the tubing or conduits; provision has been made refrigerating apparatus period.

Heretofore no adequate for the protection of the during the cleaning Itis therefore an object of my invention to More specifically, it is means for protecting the during the cleaning an object of my invention to provide a means for preventing heat transfer from the member which is being cleaned with live steam and the evaporator of the primary refrigerating apparatus.

Further objects and advantages of the present invention will be apparent from the following description,

panying the present invention is In the drawings:

reference being had to the accomdrawings, wherein a preferred form of clearly shown.

Fig. 1 is an illustration of one form of my invention partly diagrammatic;

Fig. 2 is an illustration of another form of my invention applied to a so yand da fountain installation,

(Ci. d2-glieli) Fig. 3 is an illustration of another form of my invention somewhat similar to that shown in Fig. 2.

Referring to the drawings and more particu larly to Fig. l, there is shown a refrigerant lique= fying apparatus comprising a compressor it@ for compressing refrigerant and for forwarding the compressed refrigerant to a condenser El Where the compressed refrigerant is condensed and collected in the receiver 22. From the receiver the liquid refrigerant is forwarded through the supply conduit 23 to a control valve 2Q which iS normally open and from the control valve 262i the liquid refrigerant is conducted through the conduit 25 to a iioat controlled valve 26 located Within a closed insulated vessel 2l. Thev closed insulated vessel El normally contains a volatile liquid such as a refrigerant, for example, difiuorodichloro methane, up to the level indicated by the reference character 28. This level is normally maintained by means of the float 29 which controls the opening and closing of the valve 2@ so as to admit the proper amount of liquid refrigerant into the closed Vessel 2i to maintain the normal liquid level designated by the reference character 23.

Within the closed vessel 29 and beneath the surface of the liquid refrigerant designated by reference character 28, there is provided a cooling member 3G comprising a plurality of coils of tubing immersed within the liquid refrigerant. This cooling member 3D is normally supplied with beverage, water or other iiuid to be cooled from av supply pipe 3i through a valve 32 and a supply conduit 33. The beverage, water or other iiuid to be cooled flowing through the cooling member 3U causes the liquid refrigerant within the closed vessel 2l to vaporize and to remove heat from the fluid to be cooled, thereby lowering its temperature.

The vapor within the closed vessel 2l' is returned to the compressor through the return conduit 3ft. 'Ihe compressor 2@ is driven by an electric motor which is controlled by a pressure responsive switch mechanism 36. The pressure responsive switch mechanism 36 has a bellows 31 which is connected to the return conduit 3i to cause the electric motor 35 to start at a predetermined high pressure within the return conduit 34 and to stop at a predetermined low pressure. Inasmuch as the pressure above the. liquid refrigerant in the closed vessel 21 determines its evaporating temperature, the evaporating temperature is thereby controlled by the switch mechanism 36 which is responsive to the vapor pressure. In this way the temperature of the liquid refrigerant within the closed vessel 21 is controlled so as to maintain the outlet or final temperature of the fluid flowing through the cooling member 30 at the proper temperature.

In order to clean the cooling member 30, there is provided a steam supply pipe 40 which has a branch connection 4l provided with a Valve 42 which is connected to the fluid supply conduit 33. W'hen the beverage, Water or other fluid is normally supplied to lthe cooling member 30 through the conduit 33, the valve 3 2 is open while the valve 42 remains closed. When it is desird to clean out the cooling member, the valve 32 is closed and the valve 42 is opened, permitting live steam or hot cleaning solution to pass through the cooling member 30.

In order to protect the refrigerating apparatus during this period, the valve 24 is provided Within the supply conduit to shut off the flow of liquid refrigerant to the closed vessel 21. 'Ihis valve 24 has a pressure responsive control mechanism located Within its upper portion 44 which is connected by a conduit 45 4to the return conduit 34 of a refrigerating system. When the pressure Within the closed vessel 21 becomes abnormally high because of the introduction of live steam or hot cleaning solution into the cooling coil 30, this high pressure will be conducted to the return conduit and through the conduit 45 to the pressure responsive mechanism within the valve 24 which increased pressure will cause the valve 24 to close to prevent further supply of liquid refrigerant to the closed vessel 21. In order to prevent the operation of the electric motor 35, the electric motor circuit is opened by a suitable switch 46 or other suitable means.

It is undesirable to permit the live steam within the coolingI member 30 to evaporate the liquid refrigerant within the closed vessel 21. For one thing the evaporation of the liquid refrigerant would greatly increase the starting load upon the compressor 20 and would require an increased amount of electric energy to again liquefy this refrigerant and furthermore, the live steam or hot cleaning solution would be cooled to such an extent that it would be condensed to water which would be quickly cooled and wouldthen no longer properly clean the cooling member. In order to prevent the cooling of the steam by the liquid refrigerant, I provide means for utilizing the vapor pressure within the closed vessel 21 for temporarily removing the liquid refrigerant therefrom during this cleaning period. v

In order to do this, I provide a capacity vessel 41, which has its bottom portion connected by a connecting conduit 48 to the bottom of the closed vessel 21. When the live steam or hot cleaning solution is turned into the cooling member 30, sufficient liquid refrigerant will evaporate to raise the vapor pressure above the liquid refrigerant within the closed vessel 21 to cause the liquid refrigerant to be forced downwardly through the conduit 48 up into the capacity vessel 41. The liquid level 28 during this period will be lowered to the bottom of the closed vessel 21 so that the cooling member 30 is uncovered. During this cleaning period the pressure within .the closed vessel 21 will be sufliciently high to prevent vaporization, within the capacity vessel 41 and indeed will cause any vapor Within the capacity vessel to condense during this period. Although the liquid level within the closed vessel 21 will drop during this period, thereby causing the float valve 26 to open, the supply of liquid refrigerant through the supply conduit 25 will be stopped by the closing of the valve 24 due to the high pressure existing Within the closed vessel during this period.

When the cleaning period is over, the switch 46 is closed, the valve 42 is closed and the valve 32 is opened. The closing of the switch 46 will cause the electric motor 35 to operate and cause the compressor to reduce the pressure within the closed vessel 21, The reduction of pressure Within the closed vessel 21 will reduce the temperature therein, and in this way the temperature of the closed vessel will then become less than the temperature of the capacity chamber. Due to the reduction of temperature and pressure Within the closed vessel 21, the liquid within the capacity vessel 41 will vaporize and force the remainder of the liquid through the conduit 48 back into the closed vessel 21. The capacity vessel 41 is not provided with any insulation and is exposed to room temperature so that its temperature is normally higher than the temperature within the closed vessel 21 so that any liquid which might bein the capacity vessel 41 under normal pressure conditions will immediately turn into vapor and in this way during normal operation all of the liquid refrigerant will be'kept in the closed vessel 21.

In Fig. 2, we have a modified form of the invention as applied to a soda fountain. In this figure, we have a compressor 60 for compressing the refrigerant and for forwarding the compressed refrigerant to the condenser 6| where it is liquefied and collected in the receiver 62. From the receiver 62 the liquid refrigerant is conducted through the supply conduit 63 to a T-connection 64. An expansion valve 65, preferably of the thermostatic type, is connected to the Tcon nection 64 and controls the supply of liquid refrigerant to an ice cream evaporating coil 66 located within the brine tank 61 of an ice cream cabinet and surrounding the plurality of ice cream receptacles 68. The thermostatic expansion valve 65 has an opposed dual control. One control is responsive to the pressure Within the evaporating coil 66 to close the valve upon an increase in pressure while the other control is provided by a thermostatic bulb 69 which contains a volatile fluid which is responsive to the temperature adjacent the outlet end of the evaporator coil 66. The pressure within the thermostatic bulb 69, through its connection by the tube 10 with the valve 65, acts upon a pressure responsive means within the upper portion 1| of the valve to open the valve when the thermostatic bulb 69 is at a comparatively high temperature and' pressure and tends to clo'se the Valve when the thermostatic bulb 59 is at a relatively low temperature and pressure. In this way the supply of liquid refrigerant to the evaporating coil 66 is controlled.

Vaporized refrigerant from the evaporating coil 66 is returned to the return conduit 12 which is connected to the intake portion of the compressor 60. 'I'he compressor 60 is driven by an electric motor 13, the operation of which is controlled by a pressure responsive switch 14. This pressure responsive switch 14 is operated by the bellows connected by conduit 16 to the return conduit 12. Inasmuch as the evaporating temperature of a refrigerant corresponds to its evaporating pressure, the switch 14 is responsive to the temperature within the evaporating coil 66 and thereby controls the operation of the electric motor 13 and the compressor 60 according to the accesso evaporating temperature within the evaporating coil 55.

At the other side of the T-connection tl there is connected another expansion valve 88, also of the thermostatic type, which is responsive to pressures on the outlet side of the valve and' is also responsive to pressures within a conduit 8| connected to the upper portion 82 of the valve 85 which contains a pressure responsive means, often called a thermostatic portion of the valve, which tends to open the valve upon an increase in pressure in the conduit 8| While on the other hand it tends to open the valve on a decrease in pressure in the conduit 8|. The expansion valve 88 is connected on its outlet side to an evaporating coil 83 located Within a closed Vessel 8d which is heavily insulated.

The evaporating coil 83 preferably consists of a plurality of coils of tubing and has a valve 85 connected to its outlet portion. The outlet side of the valve 85 is connected to the return conduit l2. The valve 85 is operated by means of a tube 85 which connects to the closed vessel 861i and which transmits this pressure to a pressure responsive operating mechanism located within the valve 85 which causes the valve to open at a predetermined high pressure. Within the closed vessel 8d there is also provided a cooling member 8l for cooling beverages, water or other fluid to be cooled. This cooling member 8l preferably takes the form of a plurality of coils of tubing and is supplied with the fluid to be cooled from a supply conduit 88 and a branch conduit 89 under the control of a valve 98 located in the branch conduit 89.

The cooling member 8`| is located in the lower portion of the closed vessel 86. This portion of the closed vessel 86 is normally lled with a volatile liquid, such as a refrigerant, to a level designated by the reference character 9|. When the fluid to be cooled passes through the cooling member 81, the volatile liquid within the closed vessel 86 is vaporized and condenses on the surfaces of the evaporator coil 83. This causes liquid refrigerant within the evaporator coil 83 to vaporize. The Valve 82 and particularly the valve 85 are subject to control by the pressure within the closed vessel 85|. As stated before, the evaporating temperature is governed by the evaporating pressure. In this way the supply and withdrawal of refrigerant from the evaporator coil 83 is controlled by the pressure and therefore the temperature of the refrigerant within the closed vessel 85. The valves 88 and 85 also control the evaporating pressure within the evaporating coil 83 and therefore the evaporating temperature of the coil 82. This evaporating temperature within the evaporating coil 83 controls the condensation of the vapor of the volatile liquid Within theclosed vessel 8d on the surfaces of the evaporating coil 83. In this way, by means of these two valves 88 and 85, the temperature to which the beverage, water or other fluid is cooled, is controlled.

As explained before, at different times there is a need for cleaning the inner surfaces of the cooling member 8l. In this modification a steam or hot cleaning solution supply pipe 93 is provided which is connected by means of a conduit all to the supply pipe 89. 'I'he ow of live steam or hot cleaning solution to the supply conduit 89 is controlled by a valve 95. When it is desired to clean the cooling member 81, the valve 80 is closed and the valve 95 is opened so that the live steam or hot cleaning solution is introduced into the cooling member 8l.

In order to prevent an excessive and unnecessary load upon the refrigerating system, I provide a capacity vessel 98, exposed to room temperature, which is connected at its lower en'd by a conduit 9'l to the lower end of the closed vessel 85. Normally, because of its higher temperature, the vapor pressure within the capacity vessel 88 will be sufficient to force any of the volatile liquid therefrom and to keep the liquid refrigerant in the closed vessel 813. However, when live steam or hot cleaning solution is introduced into the cooling member 8l, the temperature of the volatile liquid becomes much higher than the vapor pressure within they capacity Vessel 95 and the resulting vapor pressure within the closed vessel 8d will force the volatile liquid down through the conduit 91 up into the capacity vessel 9S so that the cooling member 8l is now exposed only to the refrigerant vapor since the removal of the volatile liquid has now uncovered the cooling member and so that heat transfer between the coolu ing member 81 and the volatile liquid is prevented. This prevents any effective transfer oi heat between the evaporating coil 83 and the cooling member 8l.- In this way the live steam within the cooling member 8l will not materially affect the evaporating coil 83 and will not materially affect the refrigerating system. It should be underl stood that this cleaning process only takes a few minutes and the system is immediately thereafter restored to normal operation.

Therefore it is not necessary to open the circuit of the compressor motor 'i3 during this period. At this time the motor 13 and the compressor Bil operate normally under control pressure of the responsive switch ld.

In Fig. 3 there is disclosed another modification which has a compressor |20 for compressing the refrigerant and forwarding the compressed refrigerant to a condenser |2| where the compressed refrigerant is liquefied and collected in a receiver |22. From the receiver |22 the liquid refrigerant is forwarded through a supply conduit |23 to an expansion valve |28 of the thermostatic type which controls the flow of liquid refrigerant through a conduit |25 to an evaporating coil |28 located within a heavily insulated closed vessel |21. At the outlet of the evaporator coil |26 there is provided a valve |28 which is provided with pressure responsive means operated by the pressure within the closed vessel |2'l through the medium of a connecting conduit |29. This valve |28 thereby controls the withdrawal of refrigerant from the evaporating coil |28 according to the pressure within the closed vessel |21. The refrigerant passing through the valve |28 is returned through a return conduit |38 to the compressor |28. The compressor |28 is driven by an electric motor |8| Whose operation is controlled by a pressure responsive switch |32 connected to the return conduit-` |38 and operated by the pressure therein. The valve |28 has a pressure responsive means actuated by the pressure on its outlet side which tends to close the valve upon an increase in pressure. This valve also has an upper thermostatic portion |33 having a pressure responsive means which tends to open the valve upon an increase in pressure within the conduit |35 which connects the thermostatic pressure responsive means to the closed vessel |21 so that this valve is also responsive to pressures within the closed vessel |21.

The insulated closed vessel |21 normally contains a volatile liquid, such as a liquid refrigerant, for example, difiuorodichloro methane, up

to a certain level |34. 'Ihe cooling member |35 preferably is made of a plurality of coils of tubing and 'is located in the lower portion of the closed vessel |21 beneath the level of the liquid refrigerant therein so that it is normally immersed within the liquid refrigerant. The cooling member |35 is supplied with the beverage, water or other vfluid to be cooled from a supply pipe |36 and a branch pipe |31 provided with a valve |38 which controls the supply of this liquid to the cooling unit.

The cooling member at times needs cleaning and for this purpose a supply of steam or hot cleaning solution pipe |39 is provided which has a branch conduit |40 provided with a valve |4| for controlling the supply of steam or hot cleaning solution to the cooling member |35. When it is desired to send live steam or hot cleaning solution into the cooling member |35, the valve |38 is closed and the valve |4| is opened for several minutes. This sends live steam or hot cleaning solution through the passages in the cooling member |35 for the purpose of cleaning the passages therein.

In order to prevent the refrigerant system from being placed under a heavy load, I have provided a capacity vessel |43 which is connected at the bottom by a conduit |44 to the bottom of the closed vessel |21. When the live steam or hot cleaning solution is caused to flow into the cooling member |35 some of the volatile liquid will vaporize and create a'relatively high pressure within the closed vessel |21. 'I'his high pressure will cause the secondary liquid refrigerant to be vessel |43 which is exposed to room temperature. This will uncover the cooling member of the secondary liquid refrigerant. The pressure within the closed vessel |21 during the cleaning period 40 is so high that it will prevent vaporizationin the 45 thereby condensing the vapor within the closed vessel I 21 to reduce the vapor pressure therein which will permit the volatile liquid in the capacity vessel to return to the closed vessel and to reestablish the normal liquid level therein. The capacity vessel |43, being at room temperature, will be lled with vapor at room temperature during the normal operation of the system. By providing the particular valve control described above, thetemperature of the fluid to be cooled is properly controlled and by providing the capacity chamber the refrigerating system is protected during the cleaning period.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form,

0 it is to be understood that other forms might be adopted, all coming within the scope of the claimsYV which follow.

What is claimed is as follows: 1. Refrigerating apparatus including a primary refrigerant circuit comprising a primary liquefying apparatus and a primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel, a thermostatic expansion valve for controlling the now of refrigerant to the evaporating coil, said thermostatic expansion valve having its thermostatic control portion connected to the closed' 75 vessel, and a coling member located in heat exforced fromthe closed vessel l 21 into the capacity change relation with the volatile liquid in the closed Vessel.

2. Refrigerating apparatus including a primary refrigerant circuit comprising a primary liquefying apparatus and a primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coi-l located in the closed vessel above the normal liquid level therein, a cooling member located within the closed vessel below the normal liquid level therein, a capacity vessel having its bottom portion connected to the bottom of the closed vessel,l and means for. conducting hot fluid into the cooling member for causing the liquid level within the closed chamber to be lowered.

3. Refrigerating apparatus including a pri- `mary refrigerant circuit comprising a primary liquefying apparatus and a primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel above the normal liquid level therein, a cooling member located within the closed vessel below the normal liquid level therein, a capacity vessel having its bottom portion connected to the bottom of the closed vessel, means for conducting the medium to be cooled to the cooling member, and means for conducting a warmer fluid to the cooling member for causing the volatile liq uid within the closed vessel to vaporize and force the volatile liquid from the closed vessel to the capacity vessel for preventing heat transfer between the cooling member and the evaporator coil.

4. Riefrigerating apparatus including a primary refrigerant circuit comprising a primary liquefying apparatus and a. primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel above the normal liquid level therein, a cooling member located within the closed vessel below the normal liquid level therein, a capacity vessel having its bottom portion connected to the bottom of the closed vessel, means for conducting the medium to be cooled to the cooling member, means for conducting a Warmer fluid to the cooling member for causing the volatile liquid within the closed vessel to vaporize and force the volatile liquid from the closed vessel to the capacity vessel for preventing heat transfer between the cooling member and the evaporator coil, and means for preventing the effective operation of the evaporator coil.

5. Refrigerating apparatus including a primary refrigerant circuit comprising a primary liquemeans, a closed vessel containing a volatile liquid, s aid primary evaporating means having an evaporating coil located in the closed vessel above the normal liquid level therein, a cooling member located within the closed vessel below the normal liquid level therein, a capacity vessel having its bottom portion connected to the bottom of the closed vessel, means for conducting tie medium to be cooled to the cooling member, means for conducting a warmer uid to the cooling member for causing the volatile. liquid within the closed vessel to vaporize and force the volatile liquid from the closed vessel to the capacity vessel for preventing heat transfer between the cooling member and the evaporator coil, and means responsive to the pressure within the primary evaprefrigerant thereto.

fying apparatus and a primary evaporating d. Refrigerating apparatus including a primary refrigerant circuit comprising a primary liquefying apparatus and a primary evaporating means, a closed. vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel, a valve responsive to pressures within the closed vessel for controlling the withdrawal of refrigerant from the evaporating coil, and a cooling member located in heat exchange relation with the volatile liquid in the closed vessel.

7. Refrigerating apparatus including a primary refrigerant circuit comprising a primary liquefying apparatus and a primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel, a valve responsive to pressures within the closed vessel for controlling the supply of refrigerant to the evaporating coil, and a cooling member located in heat exchange relation with the volatile liquid in the closed vessel.

8. Refrigerating apparatus including a primary refrigerant circuit comprising a primary liqueiying apparatus and a primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel, a valve responsive to 'pressures within the closed vessel for controlling the supply of refrigerant to the evaporating coil, a. second valve responsive to pressures within the closed vessel for controlling the withdrawal of refrigerant from the evaporating coil, and a cooling member located in heat exchange relation with the volatile liquid in the closed vessel.

9. Refrigerating apparatus including a closed vessel containing a volatile liquid and vapor from the volatile liquid to form a refrigerant evaporator therein, means for condensing the vapor, a capacity vessel having its bottom portion connected to the bottom portion of the closed vessel, a cooling member located within the closed vessel below the normal liquid level therein, means for conducting the medium to be cooled to the cooling member, and means for conducting a warmer fluid to .the cooling member for causing some of the volatile liquid within the closed vessel to vaporize and force 'the remainder of the volatile liquid from the closed vessel to the capacity vessel for preventing heat transfer between the cooling member and the evaporator.

10. Refrigerating apparatus including a closed vessel containing a volatile liquid and vapor from the volatile liquid, automatically controlled means for condensing the vapor, a float controlled valve controlling the flow of volatile liquid into said vessel, a capacity vessel connected to the closed vessel, a fluid flow conduit located in heat exchange relation with the volatile liquid within the closed vessel, means for introducing iiuid to be cooled to the conduit, andmeans for conducting a warmer iiuid to the conduit for causing some of the volatile liquid to vaporize and 5 force the remainder of the volatile liquid into the capacity vessel for preventing heat transfer between the cooling member and the volatile liquid during this period.

11. Refrigerating apparatus including a prio mary refrigerant circuit including a primary liquefying apparatus having an intake portion and a discharge portion and a primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel, a valve responsive to pressures within the closed vessel for controlling the supply of liquid refrigerant to the evaporating coil, a cooling member in heat exchange relation with vthe volatile liquid in the closed vessel, and means responsive to the pressures within the intake portion of the primary. liquefying apparatus for controlling the operation of the primary liquefying apparatus.

12. Refrigerating apparatus including a` primary refrigerant circuit including a primary liquefying apparatus having an intake portion and a discharge portion and a primary evaporating means, a closed vessel containing a. volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel, a valve responsive to pressures Within the closed vessel for controlling the supply of liquid refrigerant to the evaporating coil, a valve responsive to the pressures within the closed vessel for controlling the withdrawal of liquid refrigerant from the evaporating coil, a cooling member in heat exchange relation with the Volatile liquid in the closed vessel, and means responsive to pressures within the intake portion of the primary liquefying apparatus for controlling the operation of the primary liquefying apparatus.

13. Refrigerating apparatus including a primary refrigerant circuit comprising a primary liquefying apparatus and a primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel, means for automatically controlling the flow of liquid refrigerant into said evaporating coil, a valve responsive to pressures within the closed vessel for controlling the Withdrawal of refrigeranti from the evaporating coil, and a cooling member located in heat exchange relation with the volatile liquid in the closed vessel.

14. Refrigerating apparatus including a primary refrigerant circuit comprising a primary liquefying apparatus and a primary evaporating means, a closed vessel containing a volatile liquid, said primary evaporating means having an evaporating coil located in the closed vessel, means for automatically controlling the flow of liquid refrigerant into said evaporating coilin response to pressures within the closed vessel, a valve responsive to pressures within the closed vessel for controlling the withdrawal of refrigerant from the evaporating coil, and a cooling member located in heat exchange relation with the volatile liquid in the closed vessel.

15. Refrigerating apparatus including a primary refrigerant circuit comprising a liquefying apparatus and an evaporating means, said primary evaporating means being disposed in a closed vessel, said closed vessel containing a volatile refrigerant and forming a secondary refrigerant circuit, said secondary refrigerant circuit including a portion for evaporating refrigerant therein and a portion for condensing the evaponated refrigerant, said secondary refrigerant circuit also including a tank communicating with said portions thereof and adapted to receive volatile refrigerant from said closed vessel, and means for increasing the temperature within said closed vessel to cause the volatile liquid refrigerant to flow therefrom intosaid tank.

16. Refrigeratlng apparatus including a primary refrigerant circuit comprising a liquefying apparatus and an evaporating means, said priclosed vessel, said closed vessel containing a volatile refrigerant and forming a secondary refrigerant circuit, said secondary refrigerant circuit including a portion for evaporating refrigerant therein and a portion for condensing the evap- 5 orated refrigerant, said secondary refrigerant circuit also including a tank communicating with said portions thereof and adapted to receive volatile refrigerant from said closed vessel. and means within said closed vessel for increasing the temperature therein to cause volatile liquid refrigerant to ow therefrom into said tank.

JAMES R. KlLLEN. 

